title: Further experience with distal aortic perfusion and motor-evoked potential monitoring in the management of extent I-III thoracoabdominal aortic anuerysms.
abstract: BACKGROUND
  Prior studies indicated improved early mortality and paraplegia rates in a small cohort of patients with type I-III thoracoabdominal aortic aneurysms (TAAs) treated with atriofemoral bypass (AFB) and motor-evoked potentials (MEVPs) when compared with a propensity-matched cohort of patients treated with the clamp and sew (CS) method, wherein epidural cooling was the principal spinal cord protective adjunct. The use of AFB/MEVP increases the complexity of TAA repair and in this study, we address whether the early benefits will be sustained when this is applied to a general population with type I-III TAAs.
  
  
  METHODS
  Consecutive patients undergoing repair of nonruptured Crawford extent I-III TAAs from 1/1987 to 12/2011 were identified. Patients were stratified according to operative approach (AFB/MEVP vs CS). Endpoints included long-term survival, and the composite outcome of perioperative death and paraplegia. A multivariate, risk-adjusted model was then created to determine if operative approach independently influenced outcome.
  
  
  RESULTS
  There were 485 patients (CS = 385 [79%]; AFB/MEVP = 100 [21%]). The cohorts differed in that the AFB/MEVP group was younger (65.8 ± 12.5 years vs 70.9 ± 9.7 years; P < .001), had more extent I/II aneurysms (66% vs 50.1%; P = .005), and had more chronic dissections (30.3% vs 18.9%; P = .018). Operative variables differed in that the AFB/MEVP cohort had longer operative times (434 ± 112 minutes vs 324 ± 98 minutes; P < .001) and higher blood turnover (6028 ± 3473 mL vs 3581 ± 3111 mL; P < .0001). There was no difference in the rate of intraoperative death (AFB/MEVP = 1.0% vs CS = 0.5%; P = .50), length of intensive care unit stay (AFB/MEVP = 9.6 ± 8.6 days vs CS = 9.5 ± 12.3 days; P = .95) or hospital length of stay (AFB/MEVP = 19.9 ± 12.6 days vs CS = 21.6 ± 23.5 days; P = .49). The composite perioperative death and paraplegia rate was lower in the AFB/MEVP cohort (7% vs 19%; P = .004). The multivariate model for predictors of the composite outcome showed that AFB/MEVP was protective (odds ratio, 0.39; 95% confidence interval, 0.17-0.9; P = .028). Long-term (4-year) survival was improved in the AFB/MEVP group as well (73 ± 6% vs 60 ± 3%; P = .004).
  
  
  CONCLUSIONS
  AFB/MEVP is an independent predictor of improved perioperative death and paraplegia rates as well as long-term survival in patients undergoing repair of type I-III TAAs and is the preferred operative strategy.
authors.affiliation: Division of Vascular and Endovascular Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Robert T
authors.initials: RT
authors.lastname: Lancaster
authors.forename: Mark F
authors.initials: MF
authors.lastname: Conrad
authors.forename: Virendra I
authors.initials: VI
authors.lastname: Patel
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Cambria
authors.forename: Emel A
authors.initials: EA
authors.lastname: Ergul
authors.forename: Richard P
authors.initials: RP
authors.lastname: Cambria
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000784:Aortic Dissection / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D017545:Aortic Aneurysm, Thoracic / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D001803:Blood Transfusion; D019054:Evoked Potentials, Motor; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007362:Intensive Care Units; D053208:Kaplan-Meier Estimate; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D015999:Multivariate Analysis; D016017:Odds Ratio; D010264:Paraplegia / Q000209:etiology / Q000517:prevention & control; D010477:Perfusion / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000379:methods* / Q000401:mortality